Disposable prophy angles, such as that described in detail in U.S. Pat. No. 3,727,313, are utilized in conjunction with a dental handpiece to perform dental prophylaxis and polish teeth and other dental structures. Prophylaxis is actually performed by a flexible attachment to the tip of the prophy angle called a prophylaxis cup or prophy cup. These prophy cups can be attached to either disposable or nondisposable prophy angles. In either case, the prophy cup includes one end attached through the prophy angle to the dental handpiece and a second end for receiving and applying polishing compound to clean the teeth and other dental structures. The cup rotates at the control of the dental practitioner through a drill mechanism contained in the handpiece and prophy angle.
The second end of a prophy clip includes an interior that is a generally concave depression with sidewalls that diverge conically outwardly as the sidewalls extend away from a floor of the interior. Vanes are often attached to the sidewalls which extend from the floor to a rim of the concave interior. Most vanes extend in a plane which passes through an axis of rotation of the prophy cup.
During prophylaxis, the dental professional typically fills the cup with polishing compound and applies some of the polishing compound to the teeth to be cleaned before initiating rotation of the cup. The handpiece is then activated, causing the cup to spin about its axis of rotation and the prophy cup is moved over surfaces of the dental structures with the sidewalls of the interior flexing upon contact with surfaces of the dental structures. The vanes assist in the cleaning process by applying additional pressure to the polishing compound and the dental structures.
While these vanes have proven satisfactory in cleaning the dental structures, these vanes have proven particularly ineffective in retaining the polishing compound within the concave depression immediately prior to contacting the teeth. This is especially true because rotation of the cup is typically initiated before the polishing compound in the cup contacts the dental structures. When the cup is rotated, any polishing compound within the interior of the prophy cup is urged by centrifugal forces to migrate from the interior. As is known, centrifugal force is perpendicular to the axis of rotation. However, because the sidewalls of the concave depression of the interior are sloped outwardly, a component of that centrifugal force is directed out of the interior along the face of the sidewall. The vanes, being oriented in planes which pass through the axis of rotation, fail to inhibit this motion of the polishing compound out of the interior. As a result, the polishing compound is often flung prematurely out of the cup, wasting the compound and creating a mess.
This problem makes maintenance of a clean environment surrounding the patient more difficult. Furthermore, patient discomfort is often increased because greater amounts of polishing compound are ingested by the patient. Also, the prophylaxis operation is slowed significantly in that the dental practitioner must repeatedly fill the prophy cup with additional polishing compound. Accordingly, a need exists for a prophy cup which tends to retain polishing compound therein until the prophy cup impacts the teeth and dental structures to be cleaned, even when the prophy cup is rotating.
The following prior art reflects the state of the art of which applicant is aware and is included herewith to discharge applicant's acknowledged duty to disclose relevant prior art. It is stipulated, however, that none of these references teach singly nor render obvious when considered in any conceivable combination the nexus of the instant invention as disclosed in greater detail hereinafter and as particularly claimed.
______________________________________ PATENT NO. ISSUE DATE INVENTOR ______________________________________ 263,814 09/1882 Schmitz 1,999,488 04/1935 Swisher 2,025,779 12/1935 Roelke 2,135,933 11/1938 Blair 2,300,828 11/1942 Goldenberg 2,315,016 03/1943 Shotton 2,328,270 08/1943 Greenberg Re. 24,391 11/1957 McFadden 2,937,444 05/1960 Kern 3,163,934 01/1965 Wiseman 3,192,922 07/1965 Winkler 3,229,369 01/1966 Hoffmeister 3,421,224 01/1969 Brehm 3,727,313 04/1973 Graham 3,740,853 06/1973 Brahler 3,855,704 12/1974 Booth 3,877,574 04/1975 Killick 3,955,284 05/1976 Balson 3,987,550 10/1976 Danne 4,053,983 10/1977 Flatland 4,182,041 01/1980 Girard 4,248,589 02/1981 Lewis 4,259,071 03/1981 Warden 4,266,933 05/1981 Warden 4,365,956 12/1982 Bailey 4,693,871 09/1987 Geller 4,795,343 01/1989 Choisser 4,842,516 06/1989 Choisser 4,929,180 05/1990 Moreschini 4,941,828 07/1990 Kimura 5,020,994 06/1991 Huang 5,028,233 07/1991 Witherby 5,040,978 08/1991 Falcon 5,094,615 03/1992 Bailey 5,120,220 06/1992 Butler 5,156,547 10/1992 Bailey FOREIGN PATENT DOCUMENTS 646,193 German 06/1937 Durhager GB 2,209,284 A 10/1989 Kimura OTHER PRIOR ART Advertisement for Smart Angle, SmartPractice, Phoenix, AZ Denticator brochure, Rancho Cordova, California, 1990, entire brochure ______________________________________
The patents to Warden and Moreschini teach the use of a prophy cup with ridges on an interior surface. This invention is distinguishable from Warden and Moreschini in that, inter alia, the projections of this invention are not biased to draw polishing compound toward a floor of the interior, but rather merely act to inhibit polishing compound migration away from the floor. Also, different regions within the interior of this invention provide varying magnitudes of restraint, allowing the polishing compound to escape the interior in a controlled, consistent manner over a longer time period.